Retractable captive fastener

ABSTRACT

A captive nut device including a sleeve having a head at one end and a thin-walled portion at the other adapted to be bent outwardly to cooperate with the head in holding the sleeve to a workpiece, the sleeve having an annular groove intermediate its ends which receives a resilient split ring, the ring bearing against a nut received in the sleeve, the nut having a tapered surface extending to a shoulder at one end which is engageable by the retainer ring to limit movement in one direction, the retainer ring producing a force component as a result of its engagement with the tapered surface to hold the shoulder against the retainer ring, the nut end being fully retracted within the sleeve when the retainer ring so engages the shoulder.

United States Patent 1 I A A 1111 3,765,465

Gulistan Oct. 16, 1973 RETRACTABLE CAPTIVE FASTENER PrimaryExaminer-Edward C. Allen P12 11191 ,..l!! !s1it 9. 11122"; alibytgafi[73] Assignee: Deutsch Fastener C0rp., Los [57] ABSTRACT Angeles,Cal1f.1

A captive nut dev1ce mcludmg a sleeve having a head Flledi Jln- 5,1972at one end and a thin-walled portion at the other [21] APPL No; 215,523adapted to be bent outwardly to cooperate with the head in holding thesleeve to a workpiece, the sleeve having an annular groove intermediateits ends which US. Cl. receives a resilient ring the ring bearingagainst a In. C'- nut received, in the sleeve the nut having a taperedof Search urface extending to a houlder at one is engageable by theretainer ring to limit movement in References Cited one direction, theretainer ring producing a force UNITED STATES PATENTS component as aresult of its engagement with the ta- 3.583.461 6/1971 Klaus 151/69 Psurface to holdithe Shoulder against the retainer 5 9 ring, the nut endbeing fully retracted within the 151/69 sleeve when the retainer ring soengages the shoulder. 151/69 1,251,676 1/1918 McCaffray 2,949,143 8/1960Shur 2,972,367 2/1961 Wootton 3,080,184 3/1963 Hays 151/69 17Claims5Dl-awing Figures I2 40 r 4 v I 39 IN/ZV, 1 lmmiuflll PATENTEDBBT16 ms 3.765465 SHEET 2 or 2 I FIG. 4

- FIG.5

RETRACTABLE CAPTIVE F ASTENER BACKGROUND OF THE INVENTION 1. Field ofthe Invention This invention pertains to captive fasteners.

2. Description of Prior Art:

Captive fasteners are widely used, one major area being in the retentionof removable panels on aircraft. By being held to the panel, the captivefastener is always available for securing the panel back in place afterit has been removed. Frequently, these captive fasteners are nuts whichare axially movable in openings formed in the workpiece. A head at oneend of the nut limits the movement of the nut in one direction. The nutis circumscribed by a split ring which can engage an external shoulderto prevent movement of the nut in the opposite direction out of theopening in the workpiece. Another form of retention by means of a splitring is shown in the prior art U.S. Pat. No. 3,343,581, although, inthis instance, it is applied to a screw. In this design, the split ringis received in a groove in the interior surface ofa projecting sleeveand can slide a substantial distance along an unthreaded portion of theshank of the screw.

In some instances, panels must be installed and removed primarily withsliding or lateral movement relative to the supporting structure. Thisoccurs, for example, where curved panels are provided at the intakes foraircraft jet engines. A captive fastener of the type discussed above,after loosening, will drop downwardly relative to the panel with whichit is associated, so that it projects beneath the undersurface of thepanel. Consequently, it interferes with slidingor lateral movement ofthe panel as it is being installed or removed. Hence, such captivefasteners are not acceptable where this type of movement is required.

In some instances springs have been provided to retract captivefasteners, but springs add weight, bulk and complexity, and are subjectto breakage. These springloaded captive fasteners are relatively longand will not permit a flush installation in the secured postion.

Another difficulty occurs because the retaining rings for the captivefasteners are exposed and vulnerable to being dislodged or broken as thepanels are handled. Once a retainer ring has been knocked off thefastener, of course, it no longer can hold the fastener to the panel.Even more serious is the fact that the retainer ring may enter an areaof a machine or item of equipment where it can cause damage. For panelsused at the entrance to jet engines, a loose retainer ring may fall intothe inlet duct of the engine and subsequently cause severe harm to thecomponents of the engine.

SUMMARY OF THE INVENTION The present invention overcomes the problemsoutlined above, providing a simplifiedcaptive fastener which can be heldin a fully retracted position, and one in which the retainer ring willnot become loosened. The device includes a sleeve or grommet which isadapted to be secured in an opening in the workpiece,

such as an aircraft panel. The sleeve includes a flush head at one endand a thin-walled part at the other end, which is adapted to be bentoutwardly to form a flange cooperating with the head to hold the sleeve,in place..

Intermediate its ends, the sleeve includes an annular groove whichreceives a resilient split ring having a free diameter less than theinside diameter of the sleeve. A nut is received in the sleeve, the nuthaving a head at one end having a frustoconical undersurface which cancomplementarily engage a corresponding surface at the head end ofthesleeve. A frustoconical surface tapers toward a radial shoulderadjacent the opposite end of the nut. The threaded opening of the nutextends inwardly from thatend. The nut is longer than the sleeve, and somay move axially relative to it. The head of the nut engages the sleeveto limit such movement in one direction. The split ring, bearing againstthe surface of the nut, will engage the shoulder of the nut and preventthe nut from separating from the sleeve in the opposite direction.

The parts are proportioned such that, when the split ring engages theshoulder, the end of the nut is fully retracted into the sleeve. In thatposition, therefore, there is no projecting portion of the nut tointerfere with lateral movement of the panel. The inner surface of thesplit ring at that time bears against the tapered surface of the nutadjacent the shoulder. The compressive force exerted by the split ringagainst the frustoconical surface of the nut produces an axial forcecomponent which biases the nut axially in one direction so as to holdthe shoulder of the nut against the split ring. Therefore, the nut isheld by the split ring in the position where the end of the nut is fullyretracted into the sleeve. The split ring performs the dual functions ofpreventing removal of the nut and of retaining the nut in theretractedposition. Consequently, where several of the fasteners are usedon a single panel, all may be held in the retracted position as thepanel is installed and removed, so that the fasteners do not interferewith lateral movement of the panel.

Be being within a groove inside a sleeve and adjacent the nut at itsinner edge, the retainer ring is buried and is not subject to engagementwith external objects. It is securely and permanently held in the sleeveand will not become dislodged. Even if the retainer ring should becomebroken, it will not leave the groove and will stay within the sleeve. Asa result, the retainer ring will never enter an area, such as an engineintake duct, where it can cause damage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded elevationalview, partially in section, of the nut, grommet and retainer ring ofthis invention;

FIG. 2 is a side elevational view, partially in section, showing the nutreceived in the grommet and held in a retracted position, with thegrommet attached -to a I panel;

FIG. 3 is a plan view of the retainer ring; FIG. 4 is a longitudinalsectional view, partially in elevat ion, showing the fasterner in thefully mated position; and

FIG. 5 is an enlarged fragmentary sectional view showing the action ofthe retainer ring in holding the nut in the retracted position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The nut 10 shown in FIG. 1includes a blind tapped axial opening 11 extending inwardly from one end12. The nut 10 is of the general type shown in US. Pat. No. 3,192,980,with the end 12 being serrated, defining shallow radially extendingteeth. At the opposite end of the nut 10 is a head l3having afrustoconical undersurface 14 and a flat outer end surface 15. In thecentral part of the head 13 is a driving recess 16. The exterior surface17 of the nut that connects to the frustoconical undersurface l4 ofthehead 13 is cylindrical and extends the major portion of the length ofthe nut. In manufacturing the nut, a slight radius necessarily isproduced at the comer 18 where the cylindrical surface 17 connects tothe undersurface 14 of the head. The outer end of the surface 17connects to a tapered surface 19, which is frustoconical inconfiguration and is at a shallow angle relative to the axis of the nut10. At the apical end of the surface 19 is a radial shoulder 20 which isclose tothe outer end 12 of the nut. Beyond the shoulder 20 is a shortcylindrical surface 21, which has the same diameter as that of thesurface 17.

The nut is adapted to fit within a sleeve or grommet 22, at one end ofwhich is a head 23 having a frustoconical undersurface 24 and a radialouter end surface 25. A cylindrical exterior surface 26 connects to theundersurface 24 of the head 23 and extends to the opposite end of thegrommet22.

The bore through the grommet 22 includes a frustoconical surface 27 thatextends inwardly from the end 25 of the head 23, tapering in diameterinwardly. The inner end of the surface 27 connects to a secondfrustoconical surface 28, which has a more shallow taper than that ofthe surface 27. An annular groove 29 at the intermediate portion of thegrommet 22 has a radial wall 30 that connects to the inner end of thetapered surface 28. The groove 29 also includes a circumferentialsurface 31 and a second radial wall 32' opposite from the wall 30.Beyond the annular groove 29 is a short cylindrical surface 33,dimensioned so that it can substantially complementarily receive thesurfaces 17 and 21 of the nut. An enlarged cylindrical counterbore 34extends inwardly from the outer end of the grommet, resulting in athin-walled portion 35 at the end of the grommet. At the inner end ofthe counterbore 34 is a radial wall 36 which connects at its outer edgeto a groove 37 which extends axially inwardly a short distance from theradial wall 36. The shallow groove 37 is arcuate in contour and extendsto the circumferential wall of the counterbore 34 at the thin-walledportion 35.

Prior to introducing the nut 10 into the grommet 22, a split resilientretainer ring 39 is fitted into the annular groove 29. The insidediameter of the ring 39 in its free position is less than that of thediameter of the surface 33 of the bore of the grommet 22. Therefore,when the ring 39 is fitted into the groove 29, its inner circumferentialedge 40 is inward of the wall of the bore, whereas its outercircumferential edge 41 is between the radial walls 30 and 32 of thegroove 29 which hold the ring against axial movement. The radialthickness of the ring 39, between the circumferential surfaces 40 and41, is no greater than the depth of the groove 29. Consequently, thering 39 can be expanded so that it is entirely received within thegroove 29 and does not project inwardly past the surface 33 of the bore.This allows the nut 10 to be moved into the sleeve 22 after the ring 39has been installed in the groove 29. The free inside diameter of thering 39 is less than that of the nut, including its tapered surface 19,so that when the ring is released its inner edge 40 bears against theperiphery of the nut 10 and exerts a compressive force. When the nut 10is moved axially relative to the grommet 22, the. ring 39 slides alongthe surface of the nut. The nut 10 cannot be removed from the grommet bymoving it upwardly from the position shown in FIG. 2 because theshoulder 20 of the nut will engage the outer radial surface 42 of thering 39, acting as an abutment to preclude such separation. The nut head13 prevents separation in the other direction. With the nut 10 beinglonger than the grommet 22, the nut can move axially for a limiteddistance as determined by the positions of the nut head 13 and theshoulder 20.

With the nut 10 received in the grommet 22, the latter member may besecured to a workpiece, such as a panel 43. An opening 44 is provided inthe panel 43, substantially complementary to the cylindrical surface 26of the grommet 22. In addition, a spot face 45, complementary to'theundersurface 24 of the head 23 of the grommet, is formed at one end ofthe cylindrical opening.44. The grommet 22 is fitted into the opening inthe panel 43 so that the head 23 is entirely received within the spotface 45 and the end 25 of the grommet is flush with the outer surface 46of the panel. The parts are proportioned such that the thin-walledportion of the grommet 22 then extends beyond the opposite surface 47 ofthe panel 43. This portion of the grommet is bent outwardly to form aradial flange 48 which cooperates with the head 23 in securely holdingthe grommet 22 to the panel 43. When the flange 48 is formed, it issubstantially flush with the radial surface 36 of the grommet 22. Theflange 48 also protrudes very little past the surface 47 of the panel43, so that the grommet 22 is almost flush with the workpiece at thatend as well as the other.

The nut 10 then may be used in securing the panel 43 to an adjoiningpart, such as the member 49 shown in -FlG.'4. Normally, there will beseveral nuts 10 used in holding the panel 43 to the member 49. Thefastener assembly 50, attached to the member 49 for mating with the nut10, is of the type shown in US. Pat. No. 3,192,980. The member 49 isgiven an opening 51 through which the nut 10 can extend, while a shallowcounterbore 52 can receive the outwardly bent flange 48. Secured to theopposite side of the member 49 is a cage 53, which has outwardlyprojecting flanges 54 at one end, through which extend rivets 55 used insecuring the cage to the member 49. The rivets 55 have flush heads 56 atthe surface 57 of the member 49 adjacent the panel 43.

The sidewalls 58 of the cage 53 define a substantially square receptaclehaving an open end 59 adjacent the member 49 and a wall 60 closing theopposite end. Within the cage 53 is a two-piece receptacle 61 havingsidewalls 62 complementary to the sidewalls 58 of the cage 53. The end63 of the receptacle 61 has a circular opening 64, while the oppositeend wall 65 is spaced from the wall 60 of the cage 53 and provided witha circular opening 66. A stud 67 has a threaded shank 68 that extendsthrough the opening 66 from a flat square head 69. The head 69 is heldloosely between the walls 65 and 60, so that it is permitted limitedlateral move- 'rnent, while the square sides of the head 69 preventsubstantial rotation of it.

Around the shank 68 is a plate or washer 70, which has square sides andteeth on its outwardly facing surface 71. A compression spring 72 bearsagainst the opposite surface of the plate 70, biasing it toward the end63 of the inner receptacle 61. A tab 73 extends from one corner of theplate and into a longitudinal slot 74 in a flattened comer 75 of theinner receptacle 61. This holds the plate 70 against substantialrotation relative to the inner receptacle 61, but allows the platefloating movement laterally.

in the secured position of the fastener, the threaded shank 68 of thestud 67 is received in the opening 11 of the nut. The serrated end wall12 of the nut is engaged by the similar serrations on the surface 71 ofthe plate 70, which is held against the nut by the spring 72. When thenut is being rotated, its teeth slide across the teeth of the plate 70.When the fastener is fully tightened, the interengaging teeth of theplate 70 and the nut 10 provide a locking effect which will not permitthe nut to be loosened from vibrational forces or other serviceconditions.

In the fully secured position of the fastener, the outer surface 15 ofthe nut head 13 is substantially flush with the outer surface 25 of thegrommet 22 and with the surface 46 of the panel 43. The shallow taper 28in the interior of the grommet provides a clearance for the slightradius at the corner 18 of the nut, so that there is no interferencewith movement of the nut head 13 entirely into the grommet.

When the panel 43 is to be separated from the member 49, the nut 10 isrotated in the reverse direction to disengage the stud 67. As thisoccurs, the teeth of the plate 70 and of the nut 10 slide relative toeach other until the nut has left the inner receptacle 61. As the nut 10moves out of the receptacle 61 and disengages the shank 68, it will havebeen shifted axially to a position where its head 13 projects outwardlybeyond the end 25 of the grommet 22. The nut then may be pulled axiallyoutwardly until the radial shoulder on the periphery of the nut engagesthe retainer ring 39, as shown in FIG. 2. The inner edge 40' of the ring39 at that time bears against the tapered surface 19 of the nut adjacentthe shoulder 20. With the surface 19 tapering toward the shoulder 20,the reaction of the compression of the ring 39 on the surface 19produces an axial force component which biases the shoulder 20 againstthe outer radial surface 42 of the ring 39. Consequently, once the nutis so positioned, its tapered part 19 acts as a cam surface, and thering 39 holds the nut in the elevated position. When retracted in thismanner, the end 12 of the nut 10 will have been moved past thetransverse end surface 36 of the grommet 22, and so is entirely receivedwithin the grommet. This occurs because the shoulder 20 is near the end12 of the nut, and the ring 39 is positioned between the ends of thegrommet 22. Therefore, the nut 10 is retained in a position where itsend 12 is remote from the opening 51 and the surface 57 of the member49. The nut 10 then will not interfere with movement between the members43 and 49, even if this is relative lateral sliding motion. Where thepanel 43 is curved, or due to other circumstances, it may be necessaryto impart relative lateral movement between the parts 43 and 49 as theyare separated, complete retraction is essential. Even with the use of asubstantial number of fasteners on the panel 43, each maybe kept fullyretracted by its retainer ring so as to not interfere with slidingmovement.

Furthermore, the ring 39 will hold the nut 10 sufficiently far above thesurface 46 of the panel 43 so that it is instantly apparent, upon visualinspection, that the nut is loosened. This is a safety feature whichhelps avoid inadvertently leaving one of a plurality of nuts unsecuredwhen the panel 43 is reattached to the structure 49.

A further advantage from this design lies in the fact.

that the retainer ring 39 is permanently retained within the groove 29.It cannot be dislodged by being knocked off by striking another objector from vibrational forces. Even if the ring 39 should become broken, itcannot get out of the groove 29 because the nut 10 is adjacent to it.Therefore, adjacent machinery or equipment will not be endangered by aloose retaining ring dislodged from the fastener.

The foregoing detailed description is to be clearly understood as givenby way of illustration and example only, the spirit and scope of thisinvention being limited solely by the appended claims.

I claim:

1. A fastener comprising a sleeve adapted to fit within an opening in aworkpiece, said sleeve having a head at one end, a bore extendinginwardly from said one end, an annular groove intermediate the ends ofsaid bore, a counterbore extending inwardly from the opposite end ofsaid sleeve, thereby providing a relatively thin-walled portion of saidsleeve at said opposite end adapted to be bent outwardly to overlap thesurface of a workpiece for cooperating with said head of said sleeve inholding said sleeve to said workpiece, and a transverse surfaceinterconnecting said bore and said counterbore, said transverse surfacehaving a first substantially radial portion and a second recessedportion defined by an axially inwardly extending groove extending tosaid relatively thin-walled portion of said sleeve, whereby saidrelatively thin-walled portion is adapted to be so bent outwardly toassume substantial alignment with said substantially radial portion ofsaid transverse surface, a nut received in said sleeve,

said nut being longer than said sleeve and axially movable relativethereto, said nut including a head at one end engageable with saidsleeve for limiting the relative axial movement of said nut in onedirection, said nut having an axial threaded opening extending inwardlyfrom the opposite end thereof, said nut having an exterior shoulderadjacent said opposite end thereof, and a tapered surface having itsapical end adjacent said shoulder and extending inwardly therefrom, anda resilient split ring in said annular groove,

said ring having a free inside diameter less than the diameter of saidtapered surface adjacent said shoulder, whereby said ring is engageablewith said shoulder for limiting the axial movement of said nut relativeto said sleeve in the opposite direction, and simultaneously engageablewith said tapered surface for biasing said nut to a position where saidshoulder is so engaged by said ring.

2. A device as recited in claim 1 in which said opposite end of said nutis inwardly of said substantially radial portion of said transversesurface when said ring engages said shoulder.

a relatively short substantially cylindrical surface extending from saidsubstantial radial shoulder to said opposite end thereof, and a threadedopening extending axially inwardly 3. A device as recited in claim 1, inwhich said nut is of a length relative to said sleeve such that saidhead of said nut is spaced outwardly from said sleeve when said shoulderis in engagement with said ring.

4. A device as recited in claim 1 in which 5 from said opposite endthereof, said sleeve includes a frustoconical inner surface adand aresilient split ring,

jacent said one end thereof, said ring having outer portions received insaid ansaid head of said nut having a frustoconical undersurnulargroove,

face substantially complementarily engageable said ring having a freediameter less than. that of with said frustoconical inner surface ofsaid sleeve, said second frustoconical surface of said nut and wherebysaid head of said nut is substantially flush having an inner surfacebearing against the extewith said one end of said sleeve when saidunderrior of said nut, surface so engages said frustoconical innersursaid ring having a radial surface engageable with 'face of saidsleeve. said substantially radial shoulder while said inner 5. Afastener comprising surface of said nut engages said second frustoasleeve, said sleeve having conical surface of said nut,

a head at one end, whereby said ring produces a force tending to saidhead having a substantially radial outer surhold said substantiallyradial shoulder of said face and a frustoconical undersurface, and a nutin engagement with said substantially radial cylindrical outer surfaceextending from said surface of said ring, head to the opposite end ofsaid sleeve, said opposite end of said nut being entirely rea boreextending inwardly from said one end deceived within said sleeve whensaid substantially fined by a substantially frustoconical surfaceadradial shoulder so engages said radial surface of jacent said one end,said ring.

a substantially cylindrical surface axially inwardly 6. A device asrecited in claim 5 in which said bore of said substantiallyfrustoconical surface of said sleeve includes a second substantiallyfrustoconthereof, an annular groove intermediate said subical I surfaceextending between said first-mentioned stantially frustoconical surfaceand said substansubstantially frustoconical surface of said bore andsaid tially. cylindrical surface of said bore, annular groove.

a substantially cylindrical counterbore extending 7. In combination witha movable member for attachinwardly from said opposite end thereof, mentto another part, said member having an opening thereby providing arelatively thin-walled portion between a first surface and a secondsurface thereof,

of said sleeve at said opposite end adapted to said opening adjacentsaid first surface being defined be bent outwardly to overlap thesurface of a by a frustoconical surface, a fastener comprising workpiecefor cooperating with said head of a sleeve within said opening, saidsleeve having said sleeve in holding said sleeve to such a a head at oneend, workpiece, said head having a frustoconical undersurface andatransverse surface interconnecting said counengaging said frustoconicalsurface of said terbore and said bore, opening,

said transverse surface having a first substantially a bore extendinginwardly from said one end, an radial portion adjacent said bore andhaving a annular groove intermediate the ends of said second recessedportion defined by a relatively bore, and an opposite end includingshallow groove extending axially inwardly of said a first surfaceextending substantially radially substantially radial portion and tosaid relatively 4'5 outwardly from said bore, thin-walled portion ofsaid sleeve, a radial flange substantially aligned with said first anut, said nut having surface and overlapping said second surface of ahead at one end thereof, said member for cooperating with said head ofsaid head of said nut having a radial outer sursaid sleeve in attachingsaid sleeve to said face, a first frustoconical undersurface, and amember, driving recess extending inwardly from said and an axiallyinwardly extending arcuate groove outer surface thereof, intermediatesaid-first surface of said opposite said first frustoconicalundersurface of said end and said flange,

head of said nut being substantially complea nut received in saidsleeve, mentarily engageable with said substantially said nut beinglonger than said sleeve and axially frustoconical surface of said bore,with said movable relative thereto, outer surface of said head of saidnut then said nut including a head at one end engageable beingsubstantially flush with said outer surwith said sleeve for limiting therelative axial face of said head of said sleeve, movement of said nut inone direction,

a cylindrical surface extending from said undersursaid nut having an'axial threaded opening extendface of said head of said nut to alocation adjaing inwardly from the opposite end thereof, cent theopposite end of said nut, said nut having an exterior shoulder adjacentsaid a second frustoconical surface tapering from said opposite endthereof,

location toward said opposite end thereof, and a tapered surface havingits apical end adjaa substantially radial shoulder extending outwardlyfrom the apical end of said second frustoconical surface,

cent said shoulder and extending inwardly therefrom, and a resilientsplit ring in said annular groove,

said ring having a free inside diameter less than the relative to saidsleeve in the opposite direction, diameter of said tapered surfaceadjacent said and simultaneously engageable with said tapered shoulder,surface for biasing said nut to a position where whereby said ring isengageable with said shoulsaid shoulder is so engaged by said ring.

der for limiting the axial movement of said nut 5

1. A fastener comprising a sleeve adapted to fit within an opening in aworkpiece, said sleeve having a head at one end, a bore extendinginwardly from said one end, an annular groove intermediate the ends ofsaid bore, a counterbore extending inwardly from the opposite end ofsaid sleeve, thereby providing a relatively thin-walled portion of saidsleeve at said opposite end adapted to be bent outwardly to overlap thesurface of a workpiece for cooperating with said head of said sleeve inholding said sleeve to said workpiece, and a transverse surfaceinterconnecting said bore and said counterbore, said transverse surfacehaving a first substantially radial portion and a second recessedportion defined by an axially inwardlY extending groove extending tosaid relatively thinwalled portion of said sleeve, whereby saidrelatively thin-walled portion is adapted to be so bent outwardly toassume substantial alignment with said substantially radial portion ofsaid transverse surface, a nut received in said sleeve, said nut beinglonger than said sleeve and axially movable relative thereto, said nutincluding a head at one end engageable with said sleeve for limiting therelative axial movement of said nut in one direction, said nut having anaxial threaded opening extending inwardly from the opposite end thereof,said nut having an exterior shoulder adjacent said opposite end thereof,and a tapered surface having its apical end adjacent said shoulder andextending inwardly therefrom, and a resilient split ring in said annulargroove, said ring having a free inside diameter less than the diameterof said tapered surface adjacent said shoulder, whereby said ring isengageable with said shoulder for limiting the axial movement of saidnut relative to said sleeve in the opposite direction, andsimultaneously engageable with said tapered surface for biasing said nutto a position where said shoulder is so engaged by said ring.
 2. Adevice as recited in claim 1 in which said opposite end of said nut isinwardly of said substantially radial portion of said transverse surfacewhen said ring engages said shoulder.
 3. A device as recited in claim 1,in which said nut is of a length relative to said sleeve such that saidhead of said nut is spaced outwardly from said sleeve when said shoulderis in engagement with said ring.
 4. A device as recited in claim 1 inwhich said sleeve includes a frustoconical inner surface adjacent saidone end thereof, said head of said nut having a frustoconicalundersurface substantially complementarily engageable with saidfrustoconical inner surface of said sleeve, whereby said head of saidnut is substantially flush with said one end of said sleeve when saidundersurface so engages said frustoconical inner surface of said sleeve.5. A fastener comprising a sleeve, said sleeve having a head at one end,said head having a substantially radial outer surface and afrustoconical undersurface, and a cylindrical outer surface extendingfrom said head to the opposite end of said sleeve, a bore extendinginwardly from said one end defined by a substantially frustoconicalsurface adjacent said one end, a substantially cylindrical surfaceaxially inwardly of said substantially frustoconical surface thereof, anannular groove intermediate said substantially frustoconical surface andsaid substantially cylindrical surface of said bore, a substantiallycylindrical counterbore extending inwardly from said opposite endthereof, thereby providing a relatively thin-walled portion of saidsleeve at said opposite end adapted to be bent outwardly to overlap thesurface of a workpiece for cooperating with said head of said sleeve inholding said sleeve to such a workpiece, and a transverse surfaceinterconnecting said counterbore and said bore, said transverse surfacehaving a first substantially radial portion adjacent said bore andhaving a second recessed portion defined by a relatively shallow grooveextending axially inwardly of said substantially radial portion and tosaid relatively thin-walled portion of said sleeve, a nut, said nuthaving a head at one end thereof, said head of said nut having a radialouter surface, a first frustoconical undersurface, and a driving recessextending inwardly from said outer surface thereof, said firstfrustoconical undersurface of said head of said nut being substantiallycomplementarily engageable with said substantially frustoconical surfaceof said bore, with said outer surface of said head of said nut thenbeing substantially flush with said outer surface of said head of saidsleeve, a cylindRical surface extending from said undersurface of saidhead of said nut to a location adjacent the opposite end of said nut, asecond frustoconical surface tapering from said location toward saidopposite end thereof, a substantially radial shoulder extendingoutwardly from the apical end of said second frustoconical surface, arelatively short substantially cylindrical surface extending from saidsubstantial radial shoulder to said opposite end thereof, and a threadedopening extending axially inwardly from said opposite end thereof, and aresilient split ring, said ring having outer portions received in saidannular groove, said ring having a free diameter less than that of saidsecond frustoconical surface of said nut and having an inner surfacebearing against the exterior of said nut, said ring having a radialsurface engageable with said substantially radial shoulder while saidinner surface of said nut engages said second frustoconical surface ofsaid nut, whereby said ring produces a force tending to hold saidsubstantially radial shoulder of said nut in engagement with saidsubstantially radial surface of said ring, said opposite end of said nutbeing entirely received within said sleeve when said substantiallyradial shoulder so engages said radial surface of said ring.
 6. A deviceas recited in claim 5 in which said bore of said sleeve includes asecond substantially frustoconical surface extending between saidfirst-mentioned substantially frustoconical surface of said bore andsaid annular groove.
 7. In combination with a movable member forattachment to another part, said member having an opening between afirst surface and a second surface thereof, said opening adjacent saidfirst surface being defined by a frustoconical surface, a fastenercomprising a sleeve within said opening, said sleeve having a head atone end, said head having a frustoconical undersurface engaging saidfrustoconical surface of said opening, a bore extending inwardly fromsaid one end, an annular groove intermediate the ends of said bore, andan opposite end including a first surface extending substantiallyradially outwardly from said bore, a radial flange substantially alignedwith said first surface and overlapping said second surface of saidmember for cooperating with said head of said sleeve in attaching saidsleeve to said member, and an axially inwardly extending arcuate grooveintermediate said first surface of said opposite end and said flange, anut received in said sleeve, said nut being longer than said sleeve andaxially movable relative thereto, said nut including a head at one endengageable with said sleeve for limiting the relative axial movement ofsaid nut in one direction, said nut having an axial threaded openingextending inwardly from the opposite end thereof, said nut having anexterior shoulder adjacent said opposite end thereof, and a taperedsurface having its apical end adjacent said shoulder and extendinginwardly therefrom, and a resilient split ring in said annular groove,said ring having a free inside diameter less than the diameter of saidtapered surface adjacent said shoulder, whereby said ring is engageablewith said shoulder for limiting the axial movement of said nut relativeto said sleeve in the opposite direction, and simultaneously engageablewith said tapered surface for biasing said nut to a position where saidshoulder is so engaged by said ring.